Ultraviolet Lamp Said to Kill COVID, Leave People Unharmed

As reported in Infection Control Today® recently, ultraviolet (UV) light holds great potential as a disinfectant in general, and as a way to stop the spread of coronavirus disease 2019 (COVID-19) in particular. However, it can be tricky to use. Well, a Japanese company called Ushio thinks it might have found a way around one of the problems with UV disinfection. The company says it has developed a UV lamp that disinfects rooms even when there are people present. The product, called the Care 222 UV lamp, emits a UV wavelength of 220 nanometers. The company developed the lamp with the help of scientists at Columbia University.

Conventional UV lamps up until now have emitted a wavelength of 254 nanometers, which can harm people, penetrating skin and eyes and possibly causing genetic defects. “Thus, the germicidal lamp UV disinfection systems can mainly only be used in unoccupied spaces,” says a study in the American Journal of Infection Control (AJIC) by investigators with Hiroshima University Hospital that helped pave the way for the manufacturing of the CARE 222 UV lamp.

Ushio says that it will sell the lamp to medical facilities first. “To protect healthcare workers and to help stop the spread of SARS-CoV-2, more thorough prevention and control practices are needed,” the AJIC study states. “Since COVID-19 has become a pandemic and there are asymptomatic patients, attention is being focused on environmental disinfection in public spaces beyond healthcare settings in which many people come into contact with various surfaces.” However, the company foresees the lamps eventually being used far and wide—in buses, trains, elevators, and offices.

As reported in the online newspaper Japan Today, the Care 222 UV lamp would be installed in ceilings. When it emits the UV light, it kills 99.7% of viruses and bacteria in the air and on surfaces of objects within 8 feet of the lamp. The application takes between 6 and 8 minutes.

The device weighs 2.6 pounds and the company plans to sell them for around $2,800 a piece.

In a press release, Ushio notes that “it is important to use filtered 222nm UV-C light in occupied spaces. Unfiltered 222nm UV-C lamps will emit radiation in the 230nm (UV-C) to 320nm (UV-B) range. Irradiation without blocking these higher wavelengths of light has been reported to cause erythema and damage to the cellular DNA at considerably lower levels than filtered 222nm light.”

The AJIC study notes that “SARS-CoV-2 is mainly transmitted through infected respiratory droplets and close contact with infected people. Recent studies showed that SARS-CoV-2 can remain viable for days on surfaces under controlled experimental conditions. Furthermore, surfaces in hospitals treating patients with COVID-19 were found to be contaminated by SARS-CoV-2, suggesting that the hospital environment could be a potential medium of transmission. Therefore, if environmental disinfection is not effective, SARS-CoV-2 may spread widely and cause nosocomial infections.”